[ Identification | Description | Input parameters | Links ]

The Source_Maxwell_3 Component

Source with up to three Maxwellian distributions

Identification

• Site:
• Author: Kim Lefmann
• Origin: Risoe
• Date: March 2001

Description

A parametrised continuous source for modelling a (cubic) source
with (up to) 3 Maxwellian distributions.
The source produces a continuous spectrum.
The sampling of the neutrons is uniform in wavelength.

Units of flux: neutrons/cm^2/second/ster
(McStas units are in general neutrons/second)

Example:  PSI cold source T1=150.42 K / 2.51 AA     I1 = 3.67 E11
T2=38.74 K / 4.95 AA      I2 = 3.64 E11
T3=14.84 K / 9.5 AA       I3 = 0.95 E11

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
size	m	Edge of cube shaped source (for backward compatibility)	0
yheight	m	Height of rectangular source	0
xwidth	m	Width of rectangular source	0
Lmin	AA	Lower edge of lambda distribution
Lmax	AA	Upper edge of lambda distribution
dist	m	Distance from source to focusing rectangle; at (0,0,dist)
focus_xw	m	Width of focusing rectangle
focus_yh	m	Height of focusing rectangle
T1	K	1st temperature of thermal distribution
T2	K	2nd temperature of thermal distribution	300
T3	K	3nd temperature of - - -	300
I1	1/(cm**2*st)	flux, 1 (in flux units, see above)
I2	1/(cm**2*st)	flux, 2 (in flux units, see above)	0
I3	1/(cm**2*st)	flux, 3 - - -	0
target_index	1	relative index of component to focus at, e.g. next is +1 this is used to compute 'dist' automatically.	+1
lambda0	AA	Mean wavelength of neutrons.	0
dlambda	AA	Wavelength spread of neutrons.	0

AT (	,	,		) RELATIVE		Generate
ROTATED (	,	,		) RELATIVE

Links

• Source code for Source_Maxwell_3.comp.

---

[ Identification | Description | Input parameters | Links ]

Generated on 2025-05-08 13:31:31

---

Last Modified: Monday, 30-Jun-2025 11:05:10 CEST